In recent years, solar photovoltaic power generation has been getting attention as an electric power generation technology that does not require fuel and does not emit greenhouse effect gas. As solar cells used for solar photovoltaic power generation, thin-film solar cells composed of thin silicon such as amorphous silicon or microcrystalline silicon, or a compound thin film such as a CIS thin film are known.
A typical thin-film solar cell has an integrated structure where a first electrode, a semiconductor layer, and a second electrode are stacked in this order on a substrate, these layers are divided by partition grooves into multiple cells, and these cells are connected in series to each other. For example, a method called mechanical scribing described below is used to form partition grooves by removing the semiconductor layer and the second electrode on the first electrode.
In the mechanical scribing, a scriber needle is placed on the second electrode at a position where a partition groove is to be formed, and a predetermined pressure is applied to the scriber needle such that a tip of the scriber needle penetrates through the second electrode and the semiconductor layer and touches a surface of the first electrode. Then, the scriber needle is moved horizontally to remove a linear part of the second electrode and the semiconductor layer on the first electrode to form a partition groove (see, for example, Patent Document 1).